Ring for Prusament spool

I love Prusament filament but the spool design doesn’t work with all spool holders. Each side of the spool has a little notch in the inner rod hole that can cause trouble. 

When the spool holder rod isn’t fully solid, like those trying to limit friction, it can get stuck in that notch, completely blocking the spool and ruining your print if not more.

If you’re in this situation, no need to throw away your new spool holder or change filament brand, here is the Prusament universal spool holder ring.

This little piece covers the notch, making sure it can turn on any spool holder, like if the notches didn’t exist. It doesn’t change the inner hole diameter so it accommodates all rods. As a bonus if you print with the spool holder horizontally, it’ll limit friction to the ring and not the all spool side.

It prints without any support, using PLA ou PETG: less stringing in PLA but PETG is more ductile but works with both. You need 2 for a spool and a complete set prints in around 40 minutes (a set = 2 pieces, one for each spool side).

I used regular settings, like 0.2 Quality because I like when it looks nice but you can change those to your desires.

The only important thing is to use 3 perimeters because the 4 hooks are pretty small: if not they could break easily.

Here was the specifications when designing it :

• Of course solving the problem so I could use my new spool holders with Prusament
• Easy to print and without support
• Reusable so I don’t have to print 2 for each of my spool
• No glue, no screws and one piece
• Must be ergonomics so easy to use for quick insertion and removal
• Must not move or remove itself when in place
• Must not be responsible of a fail print by blocking in any case the rotation (this is why it is fully round and constraint)

To insert and remove, you can look at the pictures that explain how to do it.

On the ring, there is a visible mark for the notch for easy alignment. Also the ring has a visible mark for each hook to know exactly where to press with your thumb from behind.

To remove a hook, no need to break a nail, just put you thumb near the center hole and push with a light pressure on the outside: this will unclip the hook without hurting your finger.

Its more easy to do than to describe: you can practice a few times on a empty spool.